/*
 * This library is part of OpenCms -
 * the Open Source Content Management System
 *
 * Copyright (c) Alkacon Software GmbH & Co. KG (http://www.alkacon.com)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * For further information about Alkacon Software, please see the
 * company website: http://www.alkacon.com
 *
 * For further information about OpenCms, please see the
 * project website: http://www.opencms.org
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package org.opencms.ade.configuration;

import java.util.HashSet;
import java.util.Set;

/**
 * Helper class which keeps track of a set of updates to be performed in a different thread.
 *
 * New updates can be added, and all updates can be fetched and removed at the same time.
 *
 * @param <U> the type representing the updates
 */
public class CmsSynchronizedUpdateSet<U> {

    /** The set of updates to perform. */
    private Set<U> m_set = new HashSet<U>();

    /**
     * Adds a new update.<p>
     *
     * @param update the update
     */
    public synchronized void add(U update) {

        m_set.add(update);
    }

    /**
     * Removes all updates from the internal set and returns a new set containing the removed updates.<p>
     *
     * @return the removed updates
     */
    public synchronized Set<U> removeAll() {

        Set<U> result = new HashSet<U>(m_set);
        m_set.clear();
        return result;
    }

}
